Tethered fluid-filled chambers

ABSTRACT

An article of footwear may incorporate a chamber with an outer barrier and a tether element. The barrier may be formed from a polymer material that defines an interior cavity, and tether element may be located within the interior cavity and joined to opposite sides of the barrier. Upon pressurization of the chamber, the tether element may extend across the interior cavity and be placed in tension by the outward force of a pressurized fluid within the interior cavity. The tether element may have a variety of configurations. For example, the tether element may have a diagonal orientation, or different tether elements may have different lengths. A tether element may also have plates or tie pieces secured to opposite sides of the chamber, with one or more tethers extending between. Also, the tether element may include one of more sheets that extend across the interior cavity.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of prior pending nonprovisionalapplication Ser. No. 12/630,642, filed Dec. 3, 2009, the entiredisclosure of which is incorporated herein by reference.

BACKGROUND

Articles of footwear generally include two primary elements, an upperand a sole structure. The upper is formed from a variety of materialelements (e.g., textiles, foam, leather, and synthetic leather) that arestitched or adhesively bonded together to form a void on the interior ofthe footwear for comfortably and securely receiving a foot. Moreparticularly, the upper generally extends over the instep and toe areasof the foot, along the medial and lateral sides of the foot, under thefoot, and around the heel area of the foot. In some articles offootwear, such as basketball footwear and boots, the upper may extendupward and around the ankle to provide support or protection for theankle. Access to the void on the interior of the upper is generallyprovided by an ankle opening in a heel region of the footwear. A lacingsystem is often incorporated into the upper to adjust the fit of theupper, thereby permitting entry and removal of the foot from the voidwithin the upper. The lacing system also permits the wearer to modifycertain dimensions of the upper, particularly girth, to accommodate feetwith varying dimensions. In addition, the upper may include a tonguethat extends under the lacing system to enhance adjustability of thefootwear.

The sole structure is located adjacent to a lower portion of the upperand is generally positioned between the foot and the ground. In manyarticles of footwear, including athletic footwear, the sole structureconventionally incorporates an insole, a midsole, and an outsole. Theinsole is a thin compressible member located within the void andadjacent to a lower surface of the void to enhance footwear comfort. Themidsole, which may be secured to a lower surface of the upper andextends downward from the upper, forms a middle layer of the solestructure. In addition to attenuating ground reaction forces (i.e.,providing cushioning for the foot), the midsole may limit foot motionsor impart stability, for example. The outsole, which may be secured to alower surface of the midsole, forms the ground-contacting portion of thefootwear and is usually fashioned from a durable and wear-resistantmaterial that includes texturing to improve traction.

The conventional midsole is primarily formed from a foamed polymermaterial, such as polyurethane or ethylvinylacetate, that extendsthroughout a length and width of the footwear. In some articles offootwear, the midsole may include a variety of additional footwearelements that enhance the comfort or performance of the footwear,including plates, moderators, fluid-filled chambers, lasting elements,or motion control members. In some configurations, any of theseadditional footwear elements may be located between the midsole andeither of the upper and outsole, embedded within the midsole, orencapsulated by the foamed polymer material of the midsole, for example.Although many conventional midsoles are primarily formed from a foamedpolymer material, fluid-filled chambers or other non-foam structures mayform a majority of some midsole configurations.

SUMMARY

An article of footwear is disclosed below as having an upper and a solestructure secured to the upper. At least one of the upper and the solestructure incorporates a chamber with an outer barrier and a tetherelement. The barrier is formed from a polymer material that defines aninterior cavity, and the barrier has (a) a first portion that forms afirst surface of the chamber and (b) a second portion that forms anopposite second surface of the chamber. The tether element is locatedwithin the interior cavity and joined to the first portion and thesecond portion. In some configurations, the tether element may extendacross the interior cavity and is placed in tension by the outward forceof a pressurized fluid within the interior cavity, thereby preventingthe barrier from expanding outward and retaining the intended shape ofthe chamber.

The tether element may have a variety of configurations. For example,the tether element may be joined to offset areas of the first portionand the second portion of the barrier to impart a diagonal orientation.As another example, a first tether element and a second tether elementmay have different lengths, which may impart contour to the chamber. Atether element may also have a first plate or tie piece secured to thefirst portion of the barrier, a second plate or tie piece secured to thesecond portion of the barrier, and either one tether or a plurality oftethers joined to the first plate and the second plate and extendingbetween the first plate and the second plate (i.e., across the interiorcavity). In some configurations, the tether element may include a firstsheet or layer secured to the first portion of the barrier, a secondsheet or layer secured to the second portion of the barrier, and thefirst sheet and the second sheet contacting and being joined to eachother.

The advantages and features of novelty characterizing aspects of theinvention are pointed out with particularity in the appended claims. Togain an improved understanding of the advantages and features ofnovelty, however, reference may be made to the following descriptivematter and accompanying figures that describe and illustrate variousconfigurations and concepts related to the invention.

FIGURE DESCRIPTIONS

The foregoing Summary and the following Detailed Description will bebetter understood when read in conjunction with the accompanyingfigures.

FIG. 1 is a lateral side elevational view of an article of footwear.

FIG. 2 is a medial side elevational view of the article of footwear.

FIG. 3 is a cross-sectional view of the article of footwear, as definedby section line 3-3 in FIG. 2.

FIG. 4 is a perspective view of a first chamber from the article offootwear.

FIG. 5 is an exploded perspective view of the first chamber.

FIG. 6 is a side elevational view of the first chamber.

FIG. 7 is an exploded side elevational view of the first chamber.

FIGS. 8A and 8B are cross-sectional views of the first chamber, asdefined by section lines 8A and 8B in FIG. 4.

FIGS. 9A-9D are partial cross-sectional views corresponding with anenlarged area in FIG. 8A and depicting further configurations of thefirst chamber.

FIGS. 10A and 10B are cross-sectional views corresponding with FIG. 8Band depicting a force acting upon the first chamber.

FIGS. 11A-11C are perspective views depicting further configurations ofthe first chamber.

FIGS. 12A-12N are cross-sectional views corresponding with FIG. 8B anddepicting further configurations of the first chamber.

FIG. 13 is a perspective view of a second chamber.

FIG. 14 is an exploded perspective view of the second chamber.

FIG. 15 is a side elevational view of the second chamber.

FIG. 16 is an exploded side elevational view of the second chamber.

FIGS. 17A and 17B are cross-sectional views of the second chamber, asdefined by section lines 17A and 17B in FIG. 13.

FIGS. 18A-18D are cross-sectional views corresponding with FIG. 17A anddepicting further configurations of the second chamber.

FIG. 19 is a perspective view of a third chamber.

FIG. 20 is an exploded perspective view of the third chamber.

FIG. 21 is a side elevational view of the third chamber.

FIG. 22 is an exploded side elevational view of the third chamber.

FIGS. 23A and 23B are cross-sectional views of the third chamber, asdefined by section lines 23A and 23B in FIG. 19.

FIGS. 24A-24D are cross-sectional views corresponding with FIG. 23A anddepicting further configurations of the third chamber.

FIG. 25 is a perspective view of a fourth chamber.

FIG. 26 is an exploded perspective view of the fourth chamber.

FIG. 27 is a side elevational view of the fourth chamber.

FIG. 28 is an exploded side elevational view of the fourth chamber.

FIGS. 29A and 29B are cross-sectional views of the fourth chamber, asdefined by section lines 29A and 29B in FIG. 25.

FIGS. 30A-30C are cross-sectional views corresponding with FIG. 29A anddepicting further configurations of the fourth chamber.

DETAILED DESCRIPTION

The following discussion and accompanying figures disclose an article offootwear, as well as various fluid-filled chambers that may beincorporated into the footwear. Concepts related to the chambers aredisclosed with reference to footwear that is suitable for running. Thechambers are not limited to footwear designed for running, however, andmay be utilized with a wide range of athletic footwear styles, includingbasketball shoes, cross-training shoes, cycling shoes, football shoes,soccer shoes, tennis shoes, and walking shoes, for example. The chambersmay also be utilized with footwear styles that are generally consideredto be non-athletic, including dress shoes, loafers, sandals, and boots.The concepts disclosed herein may, therefore, apply to a wide variety offootwear styles, in addition to the specific style discussed in thefollowing material and depicted in the accompanying figures. Thechambers may also be utilized with a variety of other products,including backpack straps, mats for yoga, seat cushions, and protectiveapparel, for example.

General Footwear Structure

An article of footwear 10 is depicted in FIGS. 1-3 as including an upper20 and a sole structure 30. For reference purposes, footwear 10 may bedivided into three general regions: a forefoot region 11, a midfootregion 12, and a heel region 13, as shown in FIGS. 1 and 2. Footwear 10also includes a lateral side 14 and a medial side 15. Forefoot region 11generally includes portions of footwear 10 corresponding with the toesand the joints connecting the metatarsals with the phalanges. Midfootregion 12 generally includes portions of footwear 10 corresponding withthe arch area of the foot, and heel region 13 corresponds with rearportions of the foot, including the calcaneus bone. Lateral side 14 andmedial side 15 extend through each of regions 11-13 and correspond withopposite sides of footwear 10. Regions 11-13 and sides 14-15 are notintended to demarcate precise areas of footwear 10. Rather, regions11-13 and sides 14-15 are intended to represent general areas offootwear 10 to aid in the following discussion. In addition to footwear10, regions 11-13 and sides 14-15 may also be applied to upper 20, solestructure 30, and individual elements thereof.

Upper 20 is depicted as having a substantially conventionalconfiguration incorporating a plurality material elements (e.g.,textiles, foam, leather, and synthetic leather) that are stitched oradhesively bonded together to form an interior void for securely andcomfortably receiving a foot. The material elements may be selected andlocated with respect to upper 20 in order to selectively impartproperties of durability, air-permeability, wear-resistance,flexibility, and comfort, for example. An ankle opening 21 in heelregion 13 provides access to the interior void. In addition, upper 20may include a lace 22 that is utilized in a conventional manner tomodify the dimensions of the interior void, thereby securing the footwithin the interior void and facilitating entry and removal of the footfrom the interior void. Lace 22 may extend through apertures in upper20, and a tongue portion of upper 20 may extend between the interiorvoid and lace 22. Given that various aspects of the present discussionprimarily relate to sole structure 30, upper 20 may exhibit the generalconfiguration discussed above or the general configuration ofpractically any other conventional or non-conventional upper.Accordingly, the structure of upper 20 may vary significantly within thescope of the present invention.

Sole structure 30 is secured to upper 20 and has a configuration thatextends between upper 20 and the ground. In addition to attenuatingground reaction forces (i.e., providing cushioning for the foot), solestructure 30 may provide traction, impart stability, and limit variousfoot motions, such as pronation. The primary elements of sole structure30 are a midsole element 31, an outsole 32, and a chamber 33. Midsoleelement 31 is secured to a lower area of upper 20 and may be formed fromvarious polymer foam materials (e.g., polyurethane or ethylvinylacetatefoam) that extend through each of regions 11-13 and between sides 14 and15. Additionally, midsole element 31 at least partially envelops orreceives chamber 33, which will be discussed in greater detail below.Outsole 32 is secured to a lower surface of midsole element 31 and maybe formed from a textured, durable, and wear-resistant material (e.g.,rubber) that forms the ground-contacting portion of footwear 10. Inaddition to midsole element 31, outsole 32, and chamber 33, solestructure 30 may incorporate one or more support members, moderators, orreinforcing structures, for example, that further enhance the groundreaction force attenuation characteristics of sole structure 30 or theperformance properties of footwear 10. Sole structure 30 may alsoincorporate a sockliner 34, as depicted in FIG. 3, that is locatedwithin a lower portion of the void in upper 20 and is positioned tocontact a plantar (i.e., lower) surface of the foot to enhance thecomfort of footwear 10.

When incorporated into sole structure 30, chamber 33 has a shape thatfits within a perimeter of midsole element 31 and extends through heelregion 13, extends into midfoot region 12, and also extends from lateralside 14 to medial side 15. Although chamber 33 is depicted as beingexposed through the polymer foam material of midsole element 31, chamber33 may be entirely encapsulated within midsole element 31 in someconfigurations of footwear 10. When the foot is located within upper 20,chamber 33 extends under a heel area of the foot in order to attenuateground reaction forces that are generated when sole structure 30 iscompressed between the foot and the ground during various ambulatoryactivities, such as running and walking. In some configurations, chamber33 may protrude outward from midsole element 31 or may extend furtherinto midfoot region 12 and may also extend forward to forefoot region11. Accordingly, the shape and dimensions of chamber 33 may varysignificantly to extend through various areas of footwear 10. Moreover,any of a variety of other chambers 100, 200, and 300 (disclosed ingreater detail below) may be utilized in place of chamber 33 in footwear10.

First Chamber Configuration

The primary components of chamber 33, which is depicted individually inFIGS. 4-8B, are a barrier 40 and a tether element 50. Barrier 40 formsan exterior of chamber 33 and (a) defines an interior cavity thatreceives both a pressurized fluid and tether element 50 and (b) providesa durable sealed barrier for retaining the pressurized fluid withinchamber 33. The polymer material of barrier 40 includes a first or upperbarrier portion 41, an opposite second or lower barrier portion 42, anda sidewall barrier portion 43 that extends around a periphery of chamber33 and between barrier portions 41 and 42. Tether element 50 is locatedwithin the interior cavity and has a configuration that includes a firstor upper plate 51, an opposite second or lower plate 52, and a pluralityof tethers 53 that extend between plates 51 and 52. Whereas upper plate51 is secured to an inner surface of upper barrier portion 41, lowerplate 52 is secured to an inner surface of lower barrier portion 42.Either adhesive bonding or thermobonding, for example, may be utilizedto secure tether element 50 to barrier 40.

In manufacturing chamber 33, a pair of polymer sheets may be molded andbonded during a thermoforming process to define barrier portions 41-43.More particularly, the thermoforming process (a) imparts shape to one ofthe polymer sheets in order to form upper barrier portion 41, (b)imparts shape to the other of the polymer sheets in order to form lowerbarrier portion 42 and sidewall barrier portion 43, and (c) forms aperipheral bond 44 that joins a periphery of the polymer sheets andextends around an upper area of sidewall barrier portion 43. Thethermoforming process may also locate tether element 50 within chamber33 and bond tether element 50 to each of barrier portions 41 and 42.Although substantially all of the thermoforming process may be performedwith a mold, each of the various parts of the process may be performedseparately in forming chamber 33. Other processes that utilizeblowmolding, rotational molding, or the bonding of polymer sheetswithout thermoforming may also be utilized to manufacture chamber 33.

Following the thermoforming process, a fluid may be injected into theinterior cavity and pressurized. The pressurized fluid exerts an outwardforce upon barrier 40 and plates 51 and 52, which tends to separatebarrier portions 41 and 42. Tether element 50, however, is secured toeach of barrier portions 41 and 42 in order to retain the intended shapeof chamber 33 when pressurized. More particularly, tethers 53 extendacross the interior cavity and are placed in tension by the outwardforce of the pressurized fluid upon barrier 40, thereby preventingbarrier 40 from expanding outward and retaining the intended shape ofchamber 33. Whereas peripheral bond 44 joins the polymer sheets to forma seal that prevents the fluid from escaping, tether element 50 preventschamber 33 from expanding outward or otherwise distending due to thepressure of the fluid. That is, tether element 50 effectively limits theexpansion of chamber 33 to retain an intended shape of surfaces ofbarrier portions 41 and 42.

The fluid within chamber 33 may be pressurized between zero andthree-hundred-fifty kilopascals (i.e., approximately fifty-one poundsper square inch) or more. In addition to air and nitrogen, the fluid mayinclude any of the gasses disclosed in U.S. Pat. No. 4,340,626 to Rudy.In some configurations, chamber 33 may incorporate a valve or otherstructure that permits the wearer or another individual to adjust thepressure of the fluid.

A wide range of polymer materials may be utilized for barrier 40. Inselecting materials for barrier 40, engineering properties of thematerial (e.g., tensile strength, stretch properties, fatiguecharacteristics, dynamic modulus, and loss tangent) as well as theability of the material to prevent the diffusion of the fluid containedby barrier 40 may be considered. When formed of thermoplastic urethane,for example, barrier 40 may have a thickness of approximately 1.0millimeter, but the thickness may range from 0.25 to 4.0 millimeters ormore, for example. In addition to thermoplastic urethane, examples ofpolymer materials that may be suitable for barrier 40 includepolyurethane, polyester, polyester polyurethane, and polyetherpolyurethane. Barrier 40 may also be formed from a material thatincludes alternating layers of thermoplastic polyurethane andethylene-vinyl alcohol copolymer, as disclosed in U.S. Pat. Nos.5,713,141 and 5,952,065 to Mitchell, et al. A variation upon thismaterial may also be utilized, wherein a center layer is formed ofethylene-vinyl alcohol copolymer, layers adjacent to the center layerare formed of thermoplastic polyurethane, and outer layers are formed ofa regrind material of thermoplastic polyurethane and ethylene-vinylalcohol copolymer. Another suitable material for barrier 40 is aflexible microlayer membrane that includes alternating layers of a gasbarrier material and an elastomeric material, as disclosed in U.S. Pat.Nos. 6,082,025 and 6,127,026 to Bonk, et al. Additional suitablematerials are disclosed in U.S. Pat. Nos. 4,183,156 and 4,219,945 toRudy. Further suitable materials include thermoplastic films containinga crystalline material, as disclosed in U.S. Pat. Nos. 4,936,029 and5,042,176 to Rudy, and polyurethane including a polyester polyol, asdisclosed in U.S. Pat. Nos. 6,013,340; 6,203,868; and 6,321,465 to Bonk,et al.

As discussed above, tether element 50 includes upper plate 51, theopposite lower plate 52, and the plurality of tethers 53 that extendbetween plates 51 and 52. Each of plates 51 and 52 have a generallycontinuous and planar configuration. Tethers 53 are secured to each ofplates 51 and 52 and space plates 51 and 52 apart from each other. Moreparticularly, the outward force of the pressurized fluid places tethers53 in tension and restrains further outward movement of plates 51 and 52and barrier portions 41 and 42.

Plates 51 and 52 impart a particular shape and contour to the upper andlower surfaces of chamber 33. Given that plates 51 and 52 exhibit aplanar configuration, the upper and lower surfaces of chamber 33 exhibita corresponding planar configuration. As discussed in greater detailbelow, however, one or both of plates 51 and 52 may be contoured toimpart a contoured configuration to surfaces of chamber 33. Althoughplates 51 and 52 may extend across substantially all of the length andwidth of chamber 33, plates 51 and 52 are depicted in FIGS. 8A and 8B asbeing spaced inward from sidewall barrier portion 43. That is, plates 51and 52 are depicted as only extending across a portion of the length andwidth of chamber 33. In this configuration, upper plate 51 extendsadjacent to at least fifty percent of upper barrier portion 41, andlower plate 52 extends adjacent to at least fifty percent of lowerbarrier portion 42. Without tether element 50, chamber 33 wouldeffectively bulge or otherwise distend to a generally rounded shape.Plates 51 and 52, however, retain an intended shape in barrier portions41 and 42, and tethers 53 limit the degree to which plates 51 and 52 mayseparate. Given that areas where plates 51 and 52 are absent may bulgeor distend outward, extending plates 51 and 52 adjacent to at leastfifty percent of barrier portions 41 and 42 ensures that central areasof barrier portions 41 and 42 remain properly shaped. Althoughperipheral areas of barrier portions 41 and 42 may protrude outward dueto the absence of plates 51 and 52, forming chamber 33 such that plates51 and 52 extend adjacent to at least fifty percent of barrier portions41 and 42 ensures that chamber 33 remains suitably-shaped for use infootwear 10.

A variety of structures may be utilized to secure tethers 53 to each ofplates 51 and 52. As depicted in an enlarged area of FIG. 8A, forexample, tethers 53 are merely secured to upper plate 51, and a similarconfiguration may be utilized to join tethers 53 to lower plate 52. Avariety of securing structures may also be utilized. Referring to FIG.9A, ends of tethers 53 include enlarged areas that may assist withanchoring tethers 53 within upper plate 51. FIG. 9B depicts aconfiguration wherein each of tethers 53 are secured to a restraint 54located on an upper surface of upper plate 51 (i.e., between upper plate51 and upper barrier portion 41). Each of restraints 54 may have theconfiguration of a disk that is joined to an end of one of tethers 53.In another configuration, as depicted in FIG. 9C, a single tether 53extends through upper plate 51 in two locations and runs along the uppersurface of upper plate 51. The various tethers 53 may, therefore, beformed from a single strand or other element that repeatedly passesthrough plates 51 and 52. As another example, individual tethers 53 maybe secured to a lower surface of upper plate 51, as depicted in FIG. 9D,with an adhesive or thermobonding. Accordingly, tethers 51 may besecured to plates 51 and 52 in a variety of ways.

Plates 51 and 52 may be formed from a variety of materials, includingvarious polymer materials, composite materials, and metals. Moreparticularly, plates 51 and 52 may be formed from polyethylene,polypropylene, thermoplastic polyurethane, polyether block amide, nylon,and blends of these materials. Composite materials may also be formed byincorporating glass fibers or carbon fibers into the polymer materialsdiscussed above in order to enhance the overall strength of tetherelement 50. In some configurations of chamber 33, plates 51 and 52 mayalso be formed from aluminum, titanium, or steel. Although plates 51 and52 may be formed from the same materials (e.g., a composite ofpolyurethane and carbon fibers), plates 51 and 52 may be formed fromdifferent materials (e.g., a composite and aluminum, or polyurethane andpolyethylene). As a related matter, the material forming barrier 40generally has lesser stiffness than plates 51 and 52. Whereas the footmay compress barrier 40 during walking, running, or other ambulatoryactivities, plates 51 and 52 may remain more rigid and less flexiblewhen the material forming plates 51 and 52 generally has greaterstiffness than the material forming barrier 40.

Tethers 53 may be formed from any generally one-dimensional material. Asutilized with respect to the present invention, the term“one-dimensional material” or variants thereof is intended to encompassgenerally elongate materials exhibiting a length that is substantiallygreater than a width and a thickness. Accordingly, suitable materialsfor tethers 53 include various strands, filaments, fibers, yarns,threads, cables, or ropes that are formed from rayon, nylon, polyester,polyacrylic, silk, cotton, carbon, glass, aramids (e.g., para-aramidfibers and meta-aramid fibers), ultra high molecular weightpolyethylene, liquid crystal polymer, copper, aluminum, and steel.Whereas filaments have an indefinite length and may be utilizedindividually as tethers 53, fibers have a relatively short length andgenerally go through spinning or twisting processes to produce a strandof suitable length. An individual filament utilized in tethers 53 may beformed form a single material (i.e., a monocomponent filament) or frommultiple materials (i.e., a bicomponent filament). Similarly, differentfilaments may be formed from different materials. As an example, yarnsutilized as tethers 53 may include filaments that are each formed from acommon material, may include filaments that are each formed from two ormore different materials, or may include filaments that are each formedfrom two or more different materials. Similar concepts also apply tothreads, cables, or ropes. The thickness of tethers 53 may also varysignificantly to range from 0.03 millimeters to more than 5 millimeters,for example. Although one-dimensional materials will often have across-section where width and thickness are substantially equal (e.g., around or square cross-section), some one-dimensional materials may havea width that is greater than a thickness (e.g., a rectangular, oval, orotherwise elongate cross-section). Despite the greater width, a materialmay be considered one-dimensional if a length of the material issubstantially greater than a width and a thickness of the material.

Tethers 53 are arranged in rows that extend longitudinally along thelengths of plate 51 and 52. Referring to FIG. 8B, nine tethers 53 extendacross the width of chamber 33, and each of the nine tethers are withinone of the longitudinally-extending rows. Whereas the central row oftethers 53 is oriented to have a generally vertical orientation, themore peripheral rows of tethers 53 are oriented diagonally. That is,tethers 53 may be secured to offset areas of plates 51 and 52 in orderto induce the diagonal orientation. An advantage of the diagonalorientation of tethers 53 relates to the stability of footwear 10.Referring to FIG. 10A, a force 16 is shown as compressing sole structure30 and thrusting toward lateral side 14, which may correspond to acutting motion that is utilized in many athletic activities to move anindividual side-to-side. When force 16 deforms chamber 33 in thismanner, tethers 53 adjacent to medial side 15 are placed in tension dueto their sloping or diagonal orientation, as represented by variousarrows 17. The tension in tethers 53 adjacent to medial side 15 resiststhe deformation of chamber 33, thereby resisting the collapse of lateralside 14. Similarly, referring to FIG. 10B, force 16 is shown ascompressing sole structure 30 and thrusting toward medial side 15, whichmay also correspond to a cutting motion. When force 16 deforms chamber33 in this manner, tethers 53 adjacent to lateral side 14 are placed intension due to their sloping or diagonal orientation, as represented bythe various arrows 17. The tension in tethers 53 adjacent to lateralside 14 resists the deformation of chamber 33, thereby resisting thecollapse of medial side 15. Accordingly, the diagonal orientation oftethers 53 resists deformation in chamber 33, thereby enhancing theoverall stability of footwear 10 during walking, running, or otherambulatory activities.

The overall shape of chamber 33 and the areas of footwear 10 in whichchamber 33 is located may vary significantly. Referring to FIG. 11A,chamber 33 has a generally round configuration that may be locatedsolely within heel region 13, for example. Another shape is depicted inFIG. 11B, wherein chamber 33 has a configuration that extends throughboth heel region 13 and midfoot region 12. In this configuration chamber33 may replace midsole element 31 such that chamber 33 extends fromlateral side 14 to medial side 15 and from upper 20 to outsole 32. Asimilar configuration is depicted in FIG. 11C, wherein chamber 33 has ashape that fits within a perimeter of sole structure 30 and extendsunder substantially all of the foot, thereby corresponding with ageneral outline of the foot. In this configuration chamber 33 may alsoreplace midsole element 31 such that chamber 33 extends from lateralside 14 to medial side 15, from heel region 13 to forefoot region 11,and from upper 20 to outsole 32.

Although the structure of chamber 33 discussed above and depicted in thefigures provides a suitable example of a configuration that may beutilized in footwear 10, a variety of other configurations may also beutilized. Referring to FIG. 12A, chamber 33 exhibits a taperedconfiguration. One manner of imparting the tapered configuration relatesto the relative lengths of tethers 53. Whereas tethers 53 are relativelylong in the areas of chamber 33 exhibiting greater thicknesses, tethers53 are relatively short in the areas of chamber 33 exhibiting lesserthicknesses. By varying the lengths of tethers 53, therefore, tapers orother features may be incorporated into chamber 33. The taper in FIG.12A extends from lateral side 14 to medial side 15. A taper may alsoextend from heel region 13 to forefoot region 12, as in theconfiguration of chamber 33 depicted in FIG. 11C. Another configurationof chamber 33 is depicted in FIG. 12B, wherein a central area of chamber33 is depressed relative to the peripheral areas. More particularly,upper plate 51 is contoured to have a non-planar configuration, therebyforming a depression in the central area. When incorporated intofootwear 10, the depression may correspond with the location of the heelof the wearer, thereby providing an area for securely-receiving theheel. A similar depression is also formed in the configuration ofchamber 33 depicted in FIG. 11C. In other configurations, upper plate 51may be contoured to form a protruding arch support area, for example. Asa related matter, the relative lengths of tethers 53 vary throughout theconfiguration depicted in FIG. 12B. More particularly, tethers 53 in theperipheral areas have greater lengths than tethers 53 in the centralarea.

Various aspects relating to tethers 53 may also vary. Referring to FIG.12C, each of tethers 53 exhibit a diagonal orientation. In someconfigurations, tethers 53 may cross each other to form x-shapedstructures with opposing diagonal orientations, as depicted in FIG. 12D.Additionally, the spacing between adjacent tethers 53 may varysignificantly, as depicted in FIG. 12E, and tethers 53 may be absentfrom some areas of chamber 33. While tethers 53 may be formed from anygenerally one-dimensional material, a variety of other materials orstructures may be located between plates 51 and 52 to prevent barrier 40from expanding outward and retain the intended shape of chamber 33.Referring to FIG. 12F, for example, a variety of other tethers arelocated between plates 51 and 51. More particularly, a fluid-filledmember 55 and a foam member 56 are bonded to plates 51 and 52, both ofwhich may resist tension and compression. A textile member 57 may alsobe utilized and may have the configuration of either a woven or knittextile. In some configurations, textile member 57 may be a spacer knittextile. A truss member 58 may also be utilized in chamber 33 and hasthe configuration of a semi-rigid polymer element that extends betweenplates 51 and 52. Additionally, a telescoping member 59 that freelycollapses but also resists tension may be utilized. Accordingly, avariety of other materials or structures may be utilized with tethers 53or in place of tethers 53.

Although a single plate 51 and a single plate 52 may be utilized inchamber 33, some configurations may incorporate multiple plates 51 and52. Referring to FIG. 12G, two plates 51 and two plates 52 are locatedwithin the interior cavity of barrier 40. An advantage to thisconfiguration is that each of plates 51 may deflect independently whencompressed by the foot. A similar configuration is depicted in FIG. 12H,wherein a central bond 45 joins barrier portions 41 and 42 in thecentral area of chamber 33. Bond 45 may, for example, form separatesubchambers within chamber 33, which may be pressurized differently toaffect the compressibility of different areas of chamber 33. As anadditional matter, each of plates 51 or each of plates 52 may be formedfrom different materials to impart different properties to various areasof chamber 33.

A further configurations of chamber 33 is depicted in FIG. 12I asincluding a tether element 60 that has an upper tie piece 61, a lowertie piece 62, and a tether 63. Whereas upper tie piece 61 is secured,bonded, or otherwise joined to upper barrier portion 41, lower tie piece62 is secured, bonded, or otherwise joined to lower barrier portion 42.Additionally, tether 63 is joined to each of tie pieces 61 and 62 andextends through the interior cavity. In this configuration, tether 63 isplaced in tension by the outward force of the pressurized fluid withinchamber 33. Tie pieces 61 and 62 are similar to plates 51 and 52, butare generally associated with a single tether 63 or a relatively smallnumber of tethers 63, rather than multiple tethers. Although tie pieces61 and 62 may be round disks with common diameters, tie pieces 61 and 62may have any shape or size. By modifying the lengths of tethers 63,various contours may be imparted to chamber 33. For example, FIG. 12Jdepicts chamber 33 as having a tapered configuration, and FIG. 12Kdepicts chamber 33 as having a central depression. In furtherconfigurations, tie pieces 61 and 62 may be offset from each other toimpart a diagonal configuration to tethers 63, as depicted in FIG. 12L.

Some configurations of chamber 33 may have both a tether element 50 andone or more tether elements 60, as depicted in FIG. 12M. That is,chamber 33 may have (a) a first area that includes tether element 50 and(b) a second area that includes a plurality of tether elements 60. Giventhe difference in sizes of tether element 50 and the individual tetherelements 60, the compression characteristics of chamber 33 differ inareas where tether element 50 is present and in areas where tetherelements 60 are present. More particularly, the deflection of chamber 33when a force is applied to a particular area may be different, dependingupon the type of tether element that is utilized. Accordingly, tetherelement 50 and tether elements 60 may both be utilized in chamber 33 toimpart different compression characteristics to different areas ofchamber 33.

As discussed above, chamber 33 may have (a) a first area that includestether element 50 and (b) a second area that includes a plurality oftether elements 60 in order to impart different compressioncharacteristics to the first and second areas of chamber 33. As anexample, the plurality of tether elements 60 may be utilized in lateralside 14 to impart greater deflection as the heel compresses solestructure 30, and tether element 50 may be utilized in medial side 15 toimpart a stiffer deflection as the foot rolls or pronates toward medialside 15. As another example, the plurality of tether elements 60 may beutilized in heel region 13 to impart greater deflection as the heelcompresses sole structure 30, and tether element 50 may be utilized inforefoot region 11 to impart a stiffer deflection. In otherconfigurations, the plurality of tether elements 60 may be utilized inforefoot region 11 and tether elements 60 may be utilized in heel region13. In either configuration, however, tether element 50 and a pluralityof tether elements 60 may be utilized in combination to impart differentcompression characteristics to different areas of footwear 10. Moreover,any of the additional tether element configurations shown in FIG. 12Fmay be utilized in combination with tether element 50 and one or more oftether elements 60 to vary the compression characteristics in differentareas of chamber 33 or other chambers.

Some conventional chambers utilize bonds between opposite surfaces toprevent the barrier from expanding outward and retaining the intendedshape of the chamber. Often, the bonds form indentations or depressionsin the upper and lower surfaces of the chamber and have differentcompression characteristics than other areas of the chamber (i.e., theareas without the bonds). Referring to FIG. 12N, chamber 33 has aconfiguration wherein areas with the various tether elements 60 formindentations in barrier portions 41 and 42. That is, barrier portions 41and 42 form depressions in areas where tie pieces 61 and 62 are securedto barrier 40. In some configurations, these depressions may be moldedor otherwise formed in barrier portions 41 and 42, or barrier 40 maytake this shape due to the pressure of the fluid within barrier 40. Inother configurations, a variety of other tensile members (e.g., foammembers, spacer textiles) may be utilized in place of tether elements60.

Second Chamber Configuration

The various configurations of chamber 33 discussed above provideexamples of fluid-filled chambers that may be incorporated into footwear10 or other articles of footwear. A variety of other fluid-filledchambers may also be incorporated into footwear 10 or the other articlesof footwear, including a chamber 100. Referring to FIGS. 13-17B, chamber100 has a barrier 110 and a plurality of tether elements 120. Barrier110 forms an exterior of chamber 100 and defines an interior cavity forreceiving both a pressurized fluid and tether elements 120. Barrier 110includes a first or upper barrier portion 111, an opposite second orlower barrier portion 112, and a sidewall barrier portion 113 thatextends around a periphery of chamber 100 and between barrier portions111 and 112. In addition, barrier 110 includes a peripheral bond 114,which may be absent in some configurations. Tether elements 120 arelocated within the interior cavity and have the configurations oftextile or polymer sheets, for example. Either adhesive bonding orthermobonding, for example, may be utilized to secure tether elements120 to barrier 110. Any of the manufacturing processes, materials,fluids, fluid pressures, and other features of barrier 40 discussedabove may also be utilized for barrier 110.

Tether elements 120 are secured to each of barrier portions 111 and 112in order to retain the intended shape of chamber 100 when pressurized.More particularly, tether elements 120 extend across the interior cavityand are placed in tension by the outward force of the pressurized fluidupon barrier 110, thereby preventing barrier 110 from expanding outwardand retaining the intended shape of chamber 100. That is, tetherelements 120 prevent chamber 100 from expanding outward or otherwisedistending due to the pressure of the fluid.

Although a variety of materials may be utilized, tether elements 120 maybe formed from any generally two-dimensional material. As utilized withrespect to the present invention, the term “two-dimensional material” orvariants thereof is intended to encompass generally flat materialsexhibiting a length and a width that are substantially greater than athickness. Accordingly, suitable materials for tether elements 120include various textiles, polymer sheets, or combinations of textilesand polymer sheets, for example. Textiles are generally manufacturedfrom fibers, filaments, or yarns that are, for example, either (a)produced directly from webs of fibers by bonding, fusing, orinterlocking to construct non-woven fabrics and felts or (b) formedthrough a mechanical manipulation of yarn to produce a woven or knittedfabric. The textiles may incorporate fibers that are arranged to impartone-directional stretch or multi-directional stretch. The polymer sheetsmay be extruded, rolled, or otherwise formed from a polymer material toexhibit a generally flat aspect. Two-dimensional materials may alsoencompass laminated or otherwise layered materials that include two ormore layers of textiles, polymer sheets, or combinations of textiles andpolymer sheets. In addition to textiles and polymer sheets, othertwo-dimensional materials may be utilized for tether elements 120. Insome configurations, mesh materials or perforated materials may beutilized for tether elements 120.

Each of tether elements 120 are formed from a single element of atwo-dimensional material, such as a textile or polymer sheet. Moreover,each of tether elements 120 have an upper end area 121, a lower end area122, and a central area 123. Whereas upper end area 121 is secured,bonded, or otherwise joined to upper barrier portion 111, lower end area122 is secured, bonded, or otherwise joined to lower barrier portion112. In this configuration, central area 123 extends through theinterior cavity and is placed in tension by the outward force of thepressurized fluid within chamber 100.

Although the structure of chamber 100 discussed above and depicted inthe figures provides a suitable example of a configuration that may beutilized in footwear 10, a variety of other configurations may also beutilized. Referring to FIG. 18A, tether elements 120 are secured tooffset areas of barrier portions 111 and 112 in order to impart adiagonal orientation to central areas 123. More particularly, end areas121 and 122 are secured to offset locations to induce the slanting ordiagonal orientation in central areas 123. As discussed above, thediagonal orientation resists deformation in chamber 100, therebyenhancing the overall stability of footwear 10 during walking, running,or other ambulatory activities. Referring to FIG. 18B, a single tetherelement 120 is joined to barrier portions 111 and 112 in variouslocations and has a zigzagging configuration within chamber 100. Bymodifying the lengths of tether elements 120, various contours may beimparted to chamber 100. For example, FIG. 18C depicts chamber 100 ashaving a tapered configuration, and FIG. 18D depicts chamber 100 ashaving a central depression. Each of these contours are formed byselectively utilizing tether elements 120 with varying lengths.

Third Chamber Configuration

In the various configurations of chamber 100 discussed above, each oftether elements 120 are formed from a single element of atwo-dimensional material. In some configurations, two or more elementsof a two-dimensional material may be utilized to form tether elements.Referring to FIGS. 19-23B, a chamber 200 having a barrier 210 and aplurality of tether elements 220 is depicted. Barrier 210 forms anexterior of chamber 200 and defines an interior cavity for receivingboth a pressurized fluid and tether elements 220. Barrier 210 includes afirst or upper barrier portion 211, an opposite second or lower barrierportion 212, and a sidewall barrier portion 213 that extends around aperiphery of chamber 200 and between barrier portions 211 and 212. Inaddition, barrier 210 includes a peripheral bond 214, which may beabsent in some configurations. Tether elements 220 are located withinthe interior cavity and are formed from at least two elements of atwo-dimensional material, such as textile or polymer sheets. Eitheradhesive bonding or thermobonding, for example, may be utilized tosecure tether elements 220 to barrier 210.

Tether elements 220 are secured to each of barrier portions 211 and 212in order to retain the intended shape of chamber 200 when pressurized.More particularly, tether elements 220 extend across the interior cavityand are placed in tension by the outward force of the pressurized fluidupon barrier 210, thereby preventing barrier 210 from expanding outwardand retaining the intended shape of chamber 200. That is, tetherelements 220 prevent chamber 200 from expanding outward or otherwisedistending due to the pressure of the fluid. Each of tether elements 220are formed from an upper sheet 221 that is joined to upper barrierportion 211 and a lower sheet 222 that is joined to lower barrierportion 212. Each of sheets 221 and 222 have an incision or cut thatforms a central tab 223. Whereas peripheral areas of sheets 221 and 222are joined with barrier 210, tabs 223 are unsecured and extend into theinterior cavity. End areas of both tabs 223 contact each other and arejoined to secure sheets 221 and 222 together. When chamber 200 ispressurized, tabs 223 are placed in tension and extend across theinterior cavity, thereby preventing chamber 200 from expanding outwardor otherwise distending due to the pressure of the fluid.

Any of the manufacturing processes, materials, fluids, fluid pressures,and other features of barrier 40 discussed above may also be utilizedfor barrier 210. In order to prevent tabs 223 from being bonded tobarrier 210, a blocker material may be utilized. More particularly, amaterial that inhibits bonding between tabs 223 and barrier 210 (e.g.,polyethylene terephthalate, silicone, polytetrafluoroethylene) may beutilized to ensure that tabs 223 remain free to extend across theinterior cavity between barrier portions 211 and 212. In manyconfigurations, the blocker material may be located on tabs 223, but mayalso be on surfaces of barrier 210 or may be a film, for example, thatextends between tabs 223 and surfaces of barrier 210.

Although the structure of chamber 200 discussed above and depicted inthe figures provides a suitable example of a configuration that may beutilized in footwear 10, a variety of other configurations may also beutilized. Referring to FIG. 24A, tether elements 220 are secured tooffset areas of barrier portions 211 and 212 in order to impart adiagonal orientation. Referring to FIG. 24B, a single sheet 221 and asingle sheet 222 define a plurality of tabs 223. Whereas each of sheets221 and 222 may form a single tab 223, sheets 221 and 222 may formmultiple tabs 223. By modifying the lengths of tabs 223, variouscontours may be imparted to chamber 200. For example, FIG. 24C depictschamber 200 as having a tapered configuration, and FIG. 24D depictschamber 200 as having a central depression. Each of these contours areformed by selectively utilizing tabs 223 with varying lengths.

Fourth Chamber Configuration

Another configuration wherein two or more elements of a two-dimensionalmaterial are utilized to form tether elements is depicted as a chamber300 in FIGS. 25-29B. Chamber 300 having a barrier 310 and a plurality oftether elements 320. Barrier 310 forms an exterior of chamber 300 anddefines an interior cavity for receiving both a pressurized fluid andtether elements 320. Barrier 310 includes a first or upper barrierportion 311, an opposite second or lower barrier portion 312, and asidewall barrier portion 313 that extends around a periphery of chamber300 and between barrier portions 311 and 312. In addition, barrier 310includes a peripheral bond 314, which may be absent in someconfigurations. Tether elements 320 are located within the interiorcavity and are formed from at least two elements of a two-dimensionalmaterial, such as textile or polymer sheets. Either adhesive bonding orthermobonding, for example, may be utilized to secure tether elements320 to barrier 310.

Tether elements 320 are secured to each of barrier portions 311 and 212in order to retain the intended shape of chamber 300 when pressurized.More particularly, tether elements 320 extend across the interior cavityand are placed in tension by the outward force of the pressurized fluidupon barrier 310, thereby preventing barrier 310 from expanding outwardand retaining the intended shape of chamber 300. That is, tetherelements 320 prevent chamber 300 from expanding outward or otherwisedistending due to the pressure of the fluid. Each of tether elements 320are formed from an upper sheet 321 that is joined to upper barrierportion 311 and a lower sheet 322 that is joined to lower barrierportion 312. Each of sheets 321 and 322 have circular or disk-shapedconfiguration. Whereas peripheral areas of sheets 321 and 322 are joinedwith each other, central areas are joined to barrier portions 311 and312. Once placed in tension, sheets 321 and 322 may distend to form theshapes seen in the various figures. When chamber 300 is pressurized,sheets 321 and 322 are placed in tension and extend across the interiorcavity, thereby preventing chamber 300 from expanding outward orotherwise distending due to the pressure of the fluid.

Any of the manufacturing processes, materials, fluids, fluid pressures,and other features of barrier 40 discussed above may also be utilizedfor barrier 310. In order to prevent peripheral areas of sheets 321 and322 from being bonded to barrier 210, a blocker material may beutilized. More particularly, a material that inhibits bonding betweenthe peripheral areas of sheets 321 and 322 and barrier 310 may beutilized to ensure that sheets 321 and 322 remain free to extend acrossthe interior cavity.

Although the structure of chamber 300 discussed above and depicted inthe figures provides a suitable example of a configuration that may beutilized in footwear 10, a variety of other configurations may also beutilized. Referring to FIG. 30A, the peripheral areas of sheets 321 and322 are bonded to barrier 310, whereas the central areas of sheets 321and 322 are bonded to each other. By modifying the diameters or otherdimensions of sheets 321 and 322, various contours may be imparted tochamber 200. For example, FIG. 30B depicts chamber 300 as having atapered configuration, but a central depression or other contour mayalso be formed by selectively varying the dimensions of sheets 321 and322.

Conclusion

The above discussion and various figures disclose a variety offluid-filled chambers that may be utilized in footwear 10 or otherarticles of footwear, as well as a variety of other products (e.g.,backpack straps, mats for yoga, seat cushions, and protective apparel).Although many of the concepts regarding the barriers and tensileelements are discussed individually, fluid-filled chambers may gainadvantages from combinations of these concepts. That is, various typesof tether elements may be utilized in a single chamber to providedifferent properties to different areas of the chamber. For example,FIG. 30C depicts a configuration wherein chamber 300 includes each oftensile elements 60, 120, 220, and 320, as well as fluid-filled member55, foam member 56, and truss member 58. Whereas tensile elements 60,120, 220, and 320 may have a configuration that collapses with thecompression of chamber 300, members 55, 56, and 58 may form more rigidstructures that resist collapsing. This configuration may be utilized,therefore, to impart compressibility to one area of chamber 300, whilelimiting compressibility in another area. Accordingly, various types oftensile elements may be utilized to impart different properties to afluid-filled chamber.

The invention is disclosed above and in the accompanying figures withreference to a variety of configurations. The purpose served by thedisclosure, however, is to provide an example of the various featuresand concepts related to the invention, not to limit the scope of theinvention. One skilled in the relevant art will recognize that numerousvariations and modifications may be made to the configurations describedabove without departing from the scope of the present invention, asdefined by the appended claims.

The invention claimed is:
 1. An article of footwear having an upper anda sole structure secured to the upper, at least one of the upper and thesole structure incorporating a chamber comprising: an outer barrierformed from a polymer material that defines an interior cavity, thebarrier having (a) a first portion that forms a first surface of thechamber and (b) a second portion that forms an opposite second surfaceof the chamber; and a tether element located within the interior cavityand including a first sheet and a second sheet, the first sheet beingsecured to the first portion of the barrier and including a first tabportion having an integral, one-piece construction with the first sheet,the second sheet being secured to the second portion of the barrier andincluding a second tab portion having an integral, one-piececonstruction with the second sheet, the first tab portion extending awayfrom the first sheet toward the second sheet and the second tab portionextending away from the second sheet toward the first sheet, the firsttab portion and the second tab portion being joined together between thefirst sheet and the second sheet and placed under tension to restrict ashape of the chamber.
 2. The article of footwear recited in claim 1,wherein a fluid is located within the interior cavity, the fluid beingpressurized to place an outward force upon the barrier and inducetension in the tether element.
 3. The article of footwear recited inclaim 1, wherein the first sheet and the second sheet are formed from atleast one of a textile and a polymer layer.
 4. The article of footwearrecited in claim 1, wherein a periphery of the first sheet is joined toa periphery of the second sheet, a central area of the first sheet issecured to the first portion of the barrier, and a central area of thesecond sheet is secured to the second portion of the barrier.
 5. Thearticle of footwear recited in claim 1, wherein the first sheet and thesecond sheet are strips of material, a first end of the first sheetbeing secured to the first portion of the barrier, and a second end ofthe first sheet being secured to the second sheet.
 6. The article offootwear recited in claim 1, wherein the first sheet includes anincision that defines the first tab portion and a peripheral portion,the peripheral portion being secured to the first portion of thebarrier, and the first tab portion being secured to the second sheet atthe second tab portion.
 7. The article of footwear recited in claim 1,wherein the chamber extends from a forefoot region to a heel region ofthe sole structure.
 8. The article of footwear recited in claim 1,wherein the chamber extends from a lateral side to a medial side of thesole structure.
 9. The article of footwear recited in claim 1, whereinthe first sheet includes a first peripheral portion attached to thefirst portion of the barrier with the first tab portion extending fromthe first peripheral portion and the second sheet includes a secondperipheral portion attached to the second portion of the barrier withthe second tab portion extending from the second peripheral portion. 10.The article of footwear recited in claim 9, wherein the first peripheralportion defines a first opening in the first sheet and the secondperipheral portion defines a second opening in the second sheet, thefirst portion of the barrier being exposed in the first opening and thesecond portion of the barrier being exposed in the second opening. 11.The article of footwear recited in claim 10, wherein the first tabportion is cut from the first sheet and defines a shape of the firstopening.
 12. The article of footwear recited in claim 10, wherein thesecond tab portion is cut from the second sheet and defines a shape ofthe second opening.
 13. The article of footwear recited in claim 1,wherein the first tab portion includes a first side facing the secondsheet, and the second tab portion includes a second side facing thefirst sheet, the first side contacting and being joined to the secondside.
 14. The article of footwear recited in claim 1, further comprisinga blocker material operable to inhibit bonding between the barrier andthe first tab portion and between the barrier and the second tabportion.
 15. The article of footwear recited in claim 14, wherein theblocker material is disposed on the barrier.